Charles e



(No Models) o. E. CARPENTER, METHOD 0F ELECTRIC HEATING.

No. 429,562. Patented June 3, 1890n UNITED STATES PATENT OEEICE.

CHARLES E. CARPENTER, OFMINNEAPOLIS, MINNESOTA, ASSIGNOR, BY DI; REOT AND MESNE ASSIGNMENTS, TO THE OARPENTER-NEV ENS ELEO- TRO-IIEATING COMPANY, OF SAME PLACE.

METHOD OF ELECTRIC HEATING.

SPECIFICATION forming part of Letters Patent No. 429,562, dated J une 3, 1890.

Application tiled March 18, 1890. Serial No. 344,353. (No model.)

To all whom it may concern:

Be it known that I, CHARLES E. CARPENTER, a citizen of the United States, and a resident of Minneapolis, in the county of Hennepin, State of Minnesota, have invented certain new and useful Improvements in the Method of Electric Heating, of which the following is a specification.

This invention relates to improvements in 1o the method of electric heating, in which an electric current is passed through a conductor of high resistance and small capacity, and has for its object to intensify the heating effects produced in the conductor or resistance. i 5 Prior to thisinvention, so far as I am aware, the Aconductor or resistance has invariably been held in position with relation to the heating-plate without any material pressure tending to force the same toward the heatingplate, and as a result thereof the resistance, whatever its character, whether carbon, wire, or other suitable conductor, soon becomes fused and its usefulness destroyed by the shrinking away of the insulating material 2 5 under the action of the heat of the resistance, lor else short circuits are established by the fusion or fleXure of the resistance, which renders the apparatus practically useless. I have found by experience, however, that when the resistance is subjected to a constant pressure, tending to force the saine toward or against the su rface-plate which it is designed to heat, all these objectionable results are avoided and the heating effect produced is materially 3 5 intensified, because under the influence of this pressure the heat is evolved and conducted to and dissipated by the heated surface-plate in the maximum degree and without the loss of any material portion ofthe electrical energy. This method of subj ecting the resistance to pressure, tending to force it toward the surface-plate to beheated,may be carried outin innumerable forinsof apparatus, in fact in all with which I am acquainted, and is therefore not limited to any specific forni of apparatus; but for convenience of description and illustration I have shown in the accompanying drawings several different forms of apparatus upon which I have tiled 5o applications for Letters Patent of the United States, Serial Nos. 334,125, filed December 17, 1889, and 344,354, filed March 18, 1890.

In the drawings, Figure l represents a transverse vertical section through a cooking-stove embodying my invention; Fig. 2, a sectional elevation of a laundry or other heated roller; Fig. 3, a central longitudinal section of a sadiron, and Fig. 4 a similar view of a solderingiron.

In all apparatus capable of carrying out my 6o method three elements are essential-to wit,

a heated su rface-plate, an electrical resistance or conductor insulated therefrom, and means for pressing the resistance toward or against the heated surface-plate-and all of these elements will be found in each of the apparatus illustrated in the drawings.

Referring now more particularly to the drawings, let A represent the plate to be heated in all the forms of apparatus, B the 7o resistance or electrical conductor, and O an insulation of some suitable character, preferably a sheet of asbestus interposed between the resistance and the plate or body to be heated. Back of the resistance is placed a heat-insulation D, generally consisting of a thick sheet of asbestus, designed to prevent the radiation or conduction of the heat generated by the resistance and confine or force the heat toward the plate or body to be heated. 8o The means for binding these elements together under pressure may be of many kinds, being generally chosen to the form of the apparatus. For instance, in the left-hand section of Fig. 1 a rigid metallic or other plate 85 E is forced toward the heated plate, so as to bind the intermediate elements against the same by means of a coiled spring F, confined between said pressure-plate and the frame of the apparatus,while in the middle section the 9o pressure-plate is forced toward the heated plate by screws Gavorkin g through the pressure-plate and tapped into the heated plate from the under side, this arrangement being reversed in the right-hand section, in which the screw works through the heated plate or frame of the apparatus from above and is tapped into the pressure-plate.

In Fig. 2, in which the apparatus takes the form of a roller, the pressure is produced by rco an internal expansible coiled spring or band H, while in the sad-iron shown in Fig. 3 the pressure is obtained in the same manner as in the middle section of Fig. l; but in the soldering-iron shown in Fig. 4 the pressure is obtained in the reverse manner to Fig. 2 that is, by either a contractile coiled spring I or a cord or thread of asbestus, Wire, or like Wrappingwhich binds the elements upon the core or body ot the iron. As before stated, however, my method may be carried out by other forms of apparatus wholly different in construction from those herein shown and described, many forms of which have heretofore been patented; but in none of them, so far as l am aware, has the resistance ever been placed under pressure tending to bind it against the plate to be heated.

Having described my invention, what I claim, and desire to secure by Letters Patent, 1s-

l. The herein-described method of intensi` fyin g the heating eftects produced by passing CHARLES E. CARPENTER.

Vtnesses:

M. F. ScoFIELD, Roer. T. LANG. 

